A nonvolatile semiconductor memory device as typified by a flash memory is used in various applications. There is demand for further increase in the capacity of such a nonvolatile semiconductor memory device. However, the miniaturization of nonvolatile semiconductor memory devices has advanced. The fact is that the processing thereof has become difficult. For instance, in a structure in which memory cells, circuit elements and the like are arranged in two dimensions, miniaturization processing has become difficult.
In contrast, recently, a nonvolatile semiconductor memory device of a three-dimensional structure has been drawing attention. In this structure, memory cells, select gates and the like are arranged in the direction perpendicular to the substrate. In the three-dimensional structure, the capacity can be increased by increasing the number of stacked layers even if the minimum processing dimension is equal to that of the two-dimensional structure. However, miniaturization still advances also in the nonvolatile semiconductor memory device of the three-dimensional structure. For instance, even if miniaturization advances, good electrical contact is required between the electrode layer in the memory cell and the interconnect connected to this electrode layer.